Maize Dek33 encodes a pyrimidine reductase in riboflavin biosynthesis that is essential for oil-body formation and ABA biosynthesis during seed development
Maize Dek33 encodes a pyrimidine reductase in riboflavin biosynthesis that is essential for oil-body formation and ABA biosynthesis during seed development
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DOI：
10.1093/jxb/erz268
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发表时间：
2019-10-01
影响因子：
6.9
通讯作者：
Song, Rentao
中科院分区：
文献类型：
--
作者：
Dai, Dawei;Tong, Hongyang;Song, Rentao
玉米（Zea mays）缺陷型籽粒33（dek 33）突变体产生缺陷型和偶尔胎生的籽粒表型。在本研究中，我们通过定位克隆的方法克隆了Dek 33，并发现它编码核黄素生物合成中的嘧啶还原酶。在dek 33中，C-末端COG 3236结构域中的单碱基突变（G至A）导致提前终止密码子（TGA），产生仅具有DEK 33蛋白的截短形式的弱突变等位基因，其发生在比完整WT形式低得多的水平，并且具有降低的核黄素含量。dek 33突变显著影响油体形成并抑制核内复制。它还破坏了阿坝的生物合成，导致阿坝含量降低，这可能是胎生胚胎的原因。此外，我们的研究结果表明，COG 3236结构域是重要的蛋白稳定性的DEK 33。酵母双杂交实验鉴定了几种与DEK 33相互作用的蛋白质，包括RGLG 2和SnRK 1，这表明DEK 33稳定性可能存在翻译后调节。DEK 33与这些蛋白质之间的相互作用通过荧光素酶互补图像分析进一步证实。这项研究提供了一个弱突变等位基因，可用于探索种子发育过程中核黄素生物合成受损的细胞反应。我们的研究结果表明，COG 3236结构域可能是玉米中DEK 33稳定性的重要调控结构。
The maize (Zea mays) defective kernel 33 (dek33) mutant produces defective and occasionally viviparous kernel phenotypes. In this study, we cloned Dek33 by positional cloning and found that it encodes a pyrimidine reductase in riboflavin biosynthesis. In dek33, a single-base mutation (G to A) in the C-terminal COG3236 domain caused a premature stop codon (TGA), producing a weak mutant allele with only a truncated form of the DEK33 protein that occurred at much lower levels that the completed WT form, and with a reduced riboflavin content. The dek33 mutation significantly affected oil-body formation and suppressed endoreduplication. It also disrupted ABA biosynthesis, resulting in lower ABA content that might be responsible for the viviparous embryo. In addition, our results indicated that the COG3236 domain is important for the protein stability of DEK33. Yeast two-hybrid experiments identified several proteins that interacted with DEK33, including RGLG2 and SnRK1, suggesting possible post-translational regulation of DEK33 stability. The interaction between DEK33 and these proteins was further confirmed by luciferase complementation image assays. This study provides a weak mutant allele that can be utilized to explore cellular responses to impaired riboflavin biosynthesis during seed development. Our findings indicate that the COG3236 domain might be an essential regulatory structure for DEK33 stability in maize.